HIV Uses Autophagy For Its Own Means

Not satisfied with simply thwarting its host's defensive maneuvers, HIV actually twists one to its advantage, based on new findings from Kyei et al. in the July 27, 2009 issue of the Journal of Cell Biology. Vojo Deretic and colleagues suggest that autophagy—a stress response process—helps HIV to proliferate and that conversely, blocking autophagy lessens HIV production.

Reduced HIV levels were accompanied by a blockade in the processing of Gag—a key precursor protein for HIV assembly. Gag in fact localized to complexes containing an autophagy protein, LC3. "It looked paradoxical," says Deretic. "But only if you didn't know something else. And that is a finding in yeast that autophagy is not only degradative, but can also serve in some biosynthetic pathways," including the trafficking of the Cvt protein to the vacuole. Together, the results suggest that Gag may piggyback on autophagosomes or their components, perhaps for locomotive services, to complete its maturation.